Side Effects of Aventyl (Nortriptyline)
Nortriptyline (Aventyl) commonly causes anticholinergic side effects including dry mouth, constipation, blurred vision, and urinary retention, as well as cardiovascular effects such as tachycardia and orthostatic hypotension. 1
Common Side Effects
Anticholinergic Effects
- Dry mouth and, rarely, associated sublingual adenitis or gingivitis
- Blurred vision, disturbance of accommodation, mydriasis
- Constipation, paralytic ileus
- Urinary retention, delayed micturition
Cardiovascular Effects
- Hypotension, hypertension
- Tachycardia, palpitations
- Arrhythmias, heart block (in severe cases)
- Risk of myocardial infarction and stroke (rare)
Neurological Effects
- Drowsiness, dizziness, weakness, fatigue
- Headache
- Numbness, tingling, paresthesias of extremities
- Incoordination, ataxia, tremors
- Seizures (lowered seizure threshold)
Psychiatric Effects
- Confusional states (especially in the elderly)
- Anxiety, restlessness, agitation
- Insomnia, nightmares
- Exacerbation of psychosis
Less Common Side Effects
Gastrointestinal
- Nausea and vomiting
- Anorexia, epigastric distress
- Peculiar taste, stomatitis
Endocrine
- Gynecomastia in males
- Breast enlargement and galactorrhea in females
- Changes in libido, impotence
- Altered blood sugar levels
Allergic Reactions
- Skin rash, petechiae, urticaria, itching
- Photosensitization
- Edema
Hematologic
- Bone marrow depression (rare)
- Agranulocytosis (rare)
- Eosinophilia, purpura, thrombocytopenia
Important Safety Considerations
Suicidality Risk
- Increased risk of suicidal thoughts and behaviors, particularly at the beginning of treatment or when doses are adjusted 1
- Requires close monitoring for worsening depression, suicidality, or unusual changes in behavior
Cardiovascular Precautions
- Should be used with caution in patients with cardiovascular disease
- May prolong conduction time
- Can block antihypertensive action of guanethidine and similar agents
Drug Interactions
- Significant interactions with cimetidine (can increase nortriptyline levels)
- Interactions with fluoxetine (can increase nortriptyline levels)
- Enhanced response to alcohol
Dosing Considerations
- Typically started at 10-25 mg at bedtime and increased gradually to a therapeutic dose of 25-100 mg 2
- Lower starting doses (10 mg) are recommended for elderly patients 3
- Once-daily dosing at bedtime is effective and may improve adherence 4
- Therapeutic blood level "window" of 50-150 ng/mL 2
Special Populations
Elderly Patients
- More susceptible to anticholinergic effects and confusion
- Lower doses are recommended
- Despite concerns, nortriptyline has a more favorable side effect profile in the elderly compared to other tricyclic antidepressants 3
- Many somatic complaints during treatment may actually be symptoms of depression rather than medication side effects 5
Patients with Comorbidities
- Use with caution in patients with glaucoma
- Avoid in patients with seizure disorders or adjust dosing carefully
- Use cautiously in patients with hyperthyroidism or those on thyroid medication
Withdrawal Considerations
- Abrupt cessation after prolonged therapy may produce nausea, headache, and malaise
- Gradual tapering is recommended when discontinuing
Nortriptyline tends to be better tolerated than other tricyclic antidepressants like amitriptyline, with less sedation but similar effects on REM sleep 6. It is important to monitor patients closely, particularly at the beginning of treatment, and to adjust dosing based on tolerability and therapeutic response.